Lamp socket having insulation piercing means for penetrating conductors



1955 c. BRAMMING 2,726,373

LAMP SOCKET HAVING INSULATION PIERCING MEANS FOR PENETRATING CONDUCTORS Filed Sept. 8, 1954 fig. 13 fig. 3 1,3 w 15 CARL BQAMM/NG (9071mm wLaa/ma (HM EZZ QE United States Patent LAMP SOCKET HAVING INSULATION PIERCING MEANS FOR PENETRATING CONDUCT ORS Carl Bramming, Nashville, Tenn., assignor to Aladdin Industries, Incorporated, Nashville, Tenn., a corporation of Illinois Application September 8, 1954, Serial N 0. 454,708

6 Claims. (Cl. 339-99) This invention relates to improvements in lamp sockets, particularly those of the type adapted to receive lamps having threaded bases provided with central contact points.

One principal object of the invention is to provide an improved lamp socket which may be connected to the insulated conductors of a lamp cord by an extremely simple mechanical assembly operation without the necessity for stripping the insulation from the ends of the conductors.

Another object of the invention is to provide a lamp socket of an improved, greatly simplified construction which may be made and connected to a lamp cord with great facility and at an extremely low cost.

Further objects and advantages of the invention will appear from the following description, taken with the accompanying drawings, in which:

Figure 1 is a plan view of a lamp socket constituting a purely illustrative embodiment of the invention;

Figs. 2 and 3 are elevational sectional views taken at right angles through the lamp socket, generally as indicated by the lines 2-2 and 3-3 in Fig. 1.

Considered in greater detail, the drawings will be seen to illustrate an exemplary lamp socket 1 adapted to receive the screw threaded base of a lamp (not shown). In this instance the lamp socket 1 includes a generally cup-shaped outer housing'2 having a generally cylindrical side wall portion 3 rounding-into a fiat, generally horizontal lower wall 4. An axial aperture 5 is formed in the lower wall 4 to receive a tubular supporting member 6 having external threads 7 at its upper end. In order to connect the housing 2 to the tubular support 6, a horizontal mounting plate 8 is mounted in the lower end of the housing and is held in place against a shoulder 9 in any suitable manner, such as by press fitting the plate 8 into the housing 2. An internally threaded hub portion 10 is provided on the plate 8 to receive the external threads 7 on the tubular support 6. A generally cylindrical insulating lining 11 is received within the side wall portion 3 of the housing 2.

In order to make contact with a lamp base, the lamp socket 1 is provided with a contact shell 12 having a threaded portion 13 adapted to engage complementary threads on the lamp base. It will be seen that the shell 12 is received within the insulating liner 11.

At its lower end the shell 12 is formed with an inwardly extending generally radial flange 14 which supports an insulating disk 15 positioned within the lower end of the shell 12. A rivet 16 or other fastening element exends through and joins the disk 15 to an inwardly extending tab 17 formed on the flange 14. At a diametrically opposite point, a contact spring 18 is connected to the disk 15 by means of a second rivet 19 or other fastening element. It will be seen that the contact spring 18 is adapted to engage the center contact point on the conventional type lamp base. In this instance, the contact spring 18 is mounted in a recess 20 formed in the upper 2,726,373 Patented Dec. 6, 1955 side of the disk 15 and is thus held against rotation about the rivet 19.

Provision is made for connecting the lamp socket 2 to a lamp cord 21 having a pair of conductors 22 covered with insulation 23. To this end, the rivets 16 and 19 are formed with chisel pointed lower end portions 24 projecting downwardly from the shell 12. The points 24 are adapted to be received in a pair of cavity elements 25 formed in a disk-like insulating member 26 which is interposed between the mounting plate 8 and the lower end of the contact shell 12. The lower end of the shell 12 is formed with a reduced portion 27 which receives the insulating disk 15 and in turn is received within an upwardly projecting flange 28 formed on the insulating member 26.

The cavity elements 23 extend generally radially from an axial aperture 29 formed in the insulating member 26 to admit the lamp cord 21. It will be seen that the conductors 22 of the lamp cord 21 are adapted to be bent outwardly so as to be received in the cavity elements 25. To clamp the rivet points 24 against the conductors 22, two diametrically opposite screws 30 are arranged to extend through the insulating disk 15 and to be threaded into apertures 31 formed in the mounting plate 8. The rivet points 24 are adapted to penerate the insulation 23 and contact the conductors 22.

It'will be understood that the lamp socket 1 may be assembled by a series of simple mechanical operations. Initially, the insulating liner 11 and the insulating member 26 are inserted into the housing 2. Then the lamp cord 21 is brought upwardly through the tubular support 6 and the aperture 29 in the insulating member 26. The ends of the conductors 22 are fanned outwardly so as to be received in the cavities 25 formed in the member 26. Next, the shell 12 is dropped into the liner 11 with the rivet points 24 alined with the cavities 25. The screws 30 are then inserted and tightened down to force the insulating disk 15 downwardly so that the rivet points 24 will penetrate the insulation 23 on the conductors 22 and establish electrical contact with the conductors. The screws 30 serve to retain the shell 12 within the housing 2. It will be apparent that the assembly is accomplished without the necessity for stripping the insulation from the ends of the lamp cord conductors. Furthermore, it is not necessary to perform such operations as looping the ends of the conductors around anchoring screws.

It will be recognized that the components of the lamp socket may be formed by such simple and inexpensive operations as stamping and molding. Moreover, the lamp socket requires a minimum number of parts, utilizing small amounts of material. Accordingly, the entire manufacture and assembly of the lamp socket may be accomplished with great facility and at an extremely low cost. In the field, it is a simple matter to disassemble the lamp socket for replacement of the lamp cord or for any other purpose.

Various modifications, alternative constructions and equivalents may be employed without departing from the true spirit and scope of the invention as exemplified in the foregoing description and defined in the following claims.

I claim:

1. A lamp socketfor connection to a lamp cord having a pair of insulated conductors, said lamp socket comprising a threaded generally cylindrical lamp receiving shell, said shell having an inwardly extending flange at one end thereof, an insulating disk positioned in said shell in engagement with said flange, a first rivet extending through said disk and said flange adjacent one edge of said disk, a contact spring positioned on said insulating disk, a second rivet extending through said spring and said disk at a point thereon spaced from said first rivet, a housing for receiving said shell, said housing having a mounting plate thereon, an insulating plate interposed between said mounting plate and said shell, said mounting plate and said insulating plate having alinedapertures for admitting the lamp cord, said insulating plate having a diametrical cavity therein communicating with said aperture therein and underlying said rivets, said rivets having pointed lower end portions for penetrating the insulation and engaging the conductors of the lamp cor-d, said cavity being adapted to receive the ends of the insulated conductors of the lamp cord, and a plurality of screws extending through said insulating disk and said insulating plate and threaded into said mounting plate for advancing said pointed ends of said rivets into said cavity and holding said shell in assembled relation to said housing.

2. A lamp socket for connection to a pair of conductors having insulation thereon, said lamp socket comprising a threaded generally cylindrical lamp receiving shell having an inwardly extending flange at one end thereof, an insulating disk mounted in said shell against said flange, a fastener element extending through and clamping together said disk and said flange, a contact member mounted on said insulating disk inside said shell, a second fastener element extending through said disk and securing said contact member thereto, said fastener elements having pointed end portions extending outside said shell, insulating means defining a pair of cavity elements for receiving said pointed end portions, said cavity elements being adapted to receive the ends of said conductors, said pointed end portions being adapted to penetrate the in sulation on said conductors and contact the conductors, and threaded fastener means extending through said insulating disk for clamping said insulating disk and said insulating means together to force said pointed end portions against the conductors.

3. In a lamp, the combination comprising a tubular support having external threads at its upper end, a housing mounted on said tubular support, said housing having a mounting plate at the lower end thereof, said plate having an internally threaded hub portion disengageably received on said external threads of said tubular support, a threaded generally cylindrical lamp receiving shell positioned inside said housing and having an inwardly extending flange adjacent the lower end thereof, an insulating disk mounted in said shell and against said flange, a rivet extending through and joining said disk and said flange adjacent one edge of said disk, a contact spring mounted on said disk, 21 second rivet extending through and joining said contact spring and said disk at a point generally diametrically opposite said first named rivet, said rivets having pointed lower end portions extending outside said shell, an insulating member interposed between said shell and said mounting plate, said insulating member having an aperture alined with said tubular support, a lamp cord having a pair of conductors extending through said tubular support and said aperture in said insulating member, said conductors having insulation thereon, a pair of cavity elements formed in the upper side of said insulating member to receiving said pointed end portions of said rivets, said cavity elements extending generally radially from said aperture in said insulating member for receiving the ends of said conductors, and a plurality of screws extending through said insulating disk and said insulating member and threaded into said mounting plate for clamping said rivets against said conductors to force said pointed end portions of said rivets through said insulation and into engagement with said conductors, said screws retaining said shell within said housing.

4. A lamp socket for connection to a lamp cord having a pair of insulated conductors, said lamp socket comprising a threaded generally cylindrical lamp receiving shell, a first insulating member extending transversely of said shell at one end thereof, a first fastening element connecting said shell to said first insulating member, a contact spring positioned on said first insulating member, a second fastening element connecting said spring to said first insulating member, a housing for receiving said shell, said housing having a transverse mounting element thereon, a second insulating member interposed between said mounting element and said shell, said second insulating member having cavity means therein for receiving the ends of the insulated conductors of the lamp cord, said fastening elements having pointed end portions for penetrating the insulation and engaging the conductors of the lamp cord, and a plurality of screws disengageably connecting said first insulating member to said mounting element for advancing said pointed ends into said cavity means and holding said shell in said housing.

5. A lamp socket for connection to a pair of conductors having insulation thereon, said lamp socket comprising a threaded generally cylindrical lamp receiving shell, an insulating member connected to said shell, a first fastener element joining said member and said shell, a contact member mounted on said insulating member, a second fastener element joining said contact member and said insulating member, said fastener elements having pointed end portions, insulating means defining a pair of cavity eiements for receiving said pointed end portions, said cavity elements being adapted to receive the ends of the conductors, said pointed end portions being adapted to penetrate the insulation and contact the conductors, and a pluraiity of screws extending through and disengageably clamping said insulating member and said insulating means together to force said pointed end portions against the conductors.

6. in a lamp, the combinationcomprising a tubular support, a housing mounted on said tubular support, a threaded generally cylindrical lamp receiving shell positioned inside said housing, an insulating member mounted on said shell at the lower end thereof and extending transversely thereto, a fastener element joining said member said shell, a contact element mounted on said memset, a second fastener element joining said contact element and said member, said fastener elements having pointed lower end portions, an insulating element adjacent the lower end of said shell, a lamp cord having a pair of conductors with insulation thereon, a pair of cavity elements formed in the upper side of said insulating element for receiving said conductors and said pointed end portions of said fastener elements, and a plurality of screws disengageably connecting said insulating member to said housing and clamping said fastening elements against said conductors to force said pointed end portions through said insulation and into engagement with said conductors.

References Cited in the file of this patent UNITED STATES PATENTS 1,679,799 Thompson Aug. 7, 1928 1,976,492 Greene Oct. 9, 1934 FOREIGN PATENTS 1,008,396 France Feb. 20, 1952 

